Technical Field
The present disclosure relates to a display device, a test circuit, and a test method thereof.
Description of the Related Art
A display device includes various display circuits such as a display panel in which a plurality of subpixels are arranged, and a source driving circuit and a gate driving circuit for driving the display panel.
In a conventional display device, transistors, various electrodes, various signal lines, and the like are provided on a glass substrate, driving circuits that can be implemented as an integrated circuit are mounted on a printed circuit, and a display panel is electrically connected to the driving circuits through the printed circuit.
Such an existing structure is suitable for a large display device, but is not suitable for a small display device.
Meanwhile, a variety of electronic devices which require small display devices, such as a virtual reality device, an augmented reality device, and the like are emerging. Thus, a display device having a very small size has been proposed. Such a device can be called a microdisplay device.
Since a microdisplay device is formed as a semiconductor chip in the form of an integrated circuit (IC) on a silicon substrate (silicon semiconductor substrate), it is very difficult to visually discriminate the defects of the microdisplay device. In many cases, various driving circuits as well as a pixel array are integrally implemented.
Accordingly, there is a need for a method of testing a microdisplay device implemented in a different form from a conventional display device.
Since the microdisplay device is formed as a semiconductor chip on a silicon substrate, the size of the semiconductor chip increases along with an increase in the size of the microdisplay device and thereby the yield is greatly reduced.
Therefore, there is a demand for a method of testing a microdisplay device having only a small size increase of the semiconductor chip due to the testing circuit being included on the semiconductor chip.